Acrylic and vinyl/acrylic copolymer latices are well known in the art and have found extensive use in the coating, paint and analogous arts, see for example the Kirk-Othmer, Encyclopedia of Chemical Technology, 2nd Edition, Vol. 14, pages 468-470, Interscience Publishers, New York (1967). In general, the coating or paint film obtained by the use of the usual acrylic copolymer latex is dried by evaporation of the water and further curing or hardening of the film does not take place following evaporation of the water.
Dicyclopentadienyl esters of carboxylic acids were first described in U.S. Pat. No. 2,395,452 of Herman A. Bruson issued Feb. 26, 1946 and the dicyclopentadienyl esters of unsaturated fatty acids are more fully and specifically described in U.S. Pat. No. 2,414,089 of Herman A. Bruson issued Jan. 14, 1947 on a continuation-in-part of the application for said 2,395,452 patent. In U.S. Pat. No. 2,414,089, Bruson characterizes the esters of his patent as "polymerizable, autoxidizable compounds which absorb oxygen from the air to form tough, hard, solvent-insoluble compositions. They are particularly useful as coating materials, serving in this respect as drying oils which have been modified with resins." (Col. 1, lines 27-32). Dicyclopentadienyl methacrylate is described in Example 8 (Col. 6, lines 25-49) of the patent as as a colorless oil which boiled at 126.degree.-133.degree. C./8 mm and dicyclopentadienyl acrylate is described in Example 9 (Col. 6, lines 50-61) as a colorless oil which boiled at 116.degree.-122.degree. C./3-5 mm. In Example 3 (Col. 5, lines 7-18) of the patent Bruson describes the preparation of the dicyclopentadienyl ester of linseed oil fatty acids and at Col. 6, lines 62-75 states that a sample of dicyclopentadienyl linoleate, as obtained in Example 3, as mixed with lead, cobalt and manganese naphthenates as a siccative and "A film of this mixture was then formed on a steel panel which was then baked for an hour at 150.degree. C. to form a hard, tough, adherent, varnish-like coating. In a similar manner, other unsaturated fatty acid esters of hydroxydihydronordicyclopentadiene and oleic, undecylenic, clupanodonic, elaidic, eleostearic or licanic acids, for example give varnish-like coatings."
More recently the admixture of monomeric dicyclopentadienyl acrylate and/or dicyclopentadienyl methacrylate with other resins and the use of such mixtures as curable coating compositions and paints has been suggested. U.S. Pat. No. 3,772,062 of E. G. Shur and R. Dabal, issued Nov. 13, 1973 discloses an ultra-violet curable coating composition comprising a blend of (a) The diacrylate of an epichlorohydrin-bisphenol-A epoxy resin, (b) neopentyl glycol diacrylate, (c) hydroxyethyl acrylate, (d) dicyclopentadienyl acrylate and (e) a photosensitizer. This composition is coated on a substrate and the coating cured by exposure to ultra-violet irradiation. Belgian Pat. No. 852,180 of Sept. 7, 1977 to Rohm and Haas Company (U.S. priority applications Ser. Nos. 664,597 and 665,017 filed Mar. 8, 1976 in the name of W. D. Emmons, K. Nyi and P. R. Sperry) discloses coating compositions and paints which comprise a mixture of (a) an aqueous solution or dispersion of a vinyl addition polymer, (b) 1-200% by weight based on such vinyl addition polymer, of dicyclopentadienyl acrylate or dicyclopentadienyl methacrylate, and (c) a drying agent. Films deposited on test panels were cured by drying for several weeks at ambient conditions. Belgian Pat. No. 842,181 of Sept. 7, 1977 to Rohm and Haas Company (U.S. priority applications Ser. Nos. 664,597 and 665,017, filed Mar. 8, 1976 in the name of W. D. Emmons, K. Nyi and P. R. Sperry) discloses coating compositions and paints which comprise a solution or dispersion in (a) dicyclopentadienyl acrylate or dicyclopentadienyl methacrylate, which may have dissolved or dispersed therein a minor proportion of at least one other liquid, non-volatile, monoethylenically unsaturated monomer; of (b) a polyester or alkyd resin which contain unsaturated groups derived from (i) fumaric acid or maleic acid or anhydride or (ii) drying or semi-drying oils. If desired such compositions may be dispersed or emulsified in water. Films deposited on test panels were cured by drying in air for several weeks, at ambient temperatures, to give hard, durable films not susceptible to crazing, shrinkage or deformation and having improved resistance to yellowing and discoloration, solvents, alkalis, weathering, UV and other radiation.
While in the foregoing coating and paint compositions, the dicyclopentadienyl acrylate or dicyclopentadienyl methacrylate was used in its monomeric form; U.S. Pat. No. 2,462,400, issued Feb. 22, 1949 to Fred W. Hoover (duPont) discloses copolymers containing from 20 to 50% of dicyclopentadienyl methacrylate and from 80 to 50% of an ester of methacrylic acid with a saturated aliphatic monohydric alcohol having from 8 to 18 carbon atoms; and coating compositions comprising a solution in an aromatic organic, preferably hydrocarbon, solvent of such copolymers as the essential film-forming ingredient; the coating compositions of this patent also preferably contain a small amount of a drying agent. In the patent, coatings, (films) were formed by flowing the coating solution on steel panels and allowing the coatings to air dry. The coating films so obtained were initially tacky but became tackfree after about 10 hours (after the solvent had evaporated) and developed moderate resistance to xylene after 24 hours. At Col. 3, line 54 to Col. 4, line 4 of this patent, the patentee states:
"The copolymers of this invention are of outstanding utility for use in coating compositions in that they yield films which, upon air drying, are highly resistant to solvents and alkalis and yet exhibit excellent toughness and flexibility. It is to be noted that products having these characteristics are obtained only when the polymerization is carried out under certain specific conditions. For example, it is essential that the monomer contain from 20 to 50% of dihyrodicyclopentadienyl methacrylate and from 80 to 50% of an ester of methacrylic acid with a saturated aliphatic alcohol of 8 to 18 carbon atoms. Use of appreciably more than 50% of dihydrodicyclopentadienyl methacrylate results in copolymers which are brittle and field films of inferior flexibility. Use of monomer mixtures containing more than 80% of a methacrylate of an alkanol having from 8 to 18 carbon atoms, on the other hand, results in soft copolymers which give films that mar so easily that they are of limited utility. As shown in Example I, copolymers derived from methacrylates of alkanols having less than 8 carbon atoms are unattractive for use in coating compositions since the resulting films are brittle." Continuing at Col. 4, lines 13-23, he states:
"The soluble, air-drying copolymers of this invention are obtained in substantially quantitative yield only when the polymerization is carried out in the presence of a solvent for dihydrodicyclopentadienyl methacrylate. Attempts to prepare these products in reasonably high conversion by conventional emulsion or bulk polymerization techniques have always resulted in insoluble, crosslinked products which are not suitable for use in coating compositions and other important applications."